This project has recently been halted, as despite initial promising results, we have been unable to generate a replicable and reliable arterial spin labeling signal in response to painful stimuli in mice. We have explored multiple avenues to trouble-shoot and address issues, but unfortunately we believe the project has too many technically challenging issues to be pursued at this point. However, we have gained a lot of invaluable information about the effects of anesthetics, and alpha chloralose, on the physiology of mice over the course of up to two hours. This information will be useful to all investigators wishing to perform scanning studies, or any studies involving anesthesia, on the mouse. We are currently compiling this research and preparing it for publication, along with the veterinary staff at the Mouse Imaging Facility (MIF).